The aim of this study was to investigate the effect of two types of intervention (aerobic exercise and low calorie diet) on serum irisin levels and insulin resistance index in sedentary obese women. For this purpose, 30 women (mean±SD: age 41.33±4.28 yr; weight 77.43±6.85 kg) who referred to health centers in Tehran city were randomly assigned to three groups: aerobic exercise (experimental 1), low calorie diet and aerobic exercise (experimental 2) and control (each group 10 subjects). The program in experimental 1 group consisted of 90 minutes of aerobic exercise and running on a treadmill for 15.18±5.63 minutes, 4 sessions a week for 16 weeks. Experimental 2 group followed a diet with caloric restriction and physical activity equal to energy expenditure of experimental 1 group. Serum irisin, glucose, insulin and insulin resistance were measured using homeostatic model assessment (HOMA-IR) before and after 16 weeks of intervention. Weight, BMI, WHR, serum irisin, fasting glucose, fasting insulin and HOMA-IR decreased significantly after weight loss induced by aerobic exercise and caloric restriction (P<0.05). A significant correlation was observed between changes of serum irisin and changes of weight, WHR and HOMA-IR (P<0.05). It seems that 16 weeks of aerobic exercise and low caloric diet influenced the reduction of serum irisin, insulin resistance index and anthropometric profiles in sedentary obese women.

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